Model output discussion 25th Jan - The final third of winter beckons..

[Ali1977]

Another good GFS with the continental feed starting around day 8, looks like a reload of colder air over West Russia that could link in with the weaker Easterly and bring something colder out way.  The heights in Scandy look very strong again, and potentially lie at a better angle and are definately halting and pushing the Atlantic back.

 

By next Wed the 12z has us with snow flurries off the North Sea.

Edited January 31, 2017 by Ali1977

[Singularity]

 

Well, that low sure is keen to get away from the steering flow of the main Atlantic jet stream that's for sure!

UKMO produces a mighty low to stand-off against the mighty block. It's actually helpful if the low swinging in at +120 as shown above phases nicely with the broader trough, as that keeps it further west. Initially it's not the best for advecting warm air up the west flank of the block, but as the storm winds down the upstream forcing from the MJO should start to kick in, hence there's good scope for that trough to possess little eastward momentum against the block. Getting it to disrupt with another secondary low sliding SE to advect the deep cold west in the 7-10 day range, well that's another matter...!

[frosty ground]

So the GFS 12Z run show cold pushing in from the east and undercutting a front from the west.

[Seasonality]

6 minutes ago, IDO said:

I think I am missing something as the last three days have been wet and the next 7/8 are forecast to be similar, with about 6 more spells of rain incoming from the west!!!

For the UK it has not really made a difference and I for one never expected full on zonal once the PV to the NW dissipates (in a week or so). So we still would have had the forecast 10 day or so spell of Atlantic, maybe the UK the end of the line rather than Europe, but essentially the same either way! IMO that was a good spot by the models of this westerly flow and as our many years of experience tells us the models probably overplayed the Atlantic viz the stubborness of the block. I could argue that if the block was over run by the Atlantic then any forcing may have been more favourable to the UK re an Atlantic ridge rather than having to rely on the retrogression of the block to our east, which rarely goes to plan?

There remains much uncertainty, with several possible outcomes, from UK high to euro block to maybe a bit higher blocking. The models tend to play around with these possibilities at this range and anybodies guess? What we do need is this downwelling from the warming to favour the UK as for us in the south it may be our last chance of decent snow chances.

My thoughts are that the models are over zealous when a new signal is signposted and that they are more likely than not over doing the heights, as they have all winter, so I expect the models to reflect that in the next day or so (NB. As when a zonal spell is spotted the Atlantic is overdone, when blocking is modelled, they over play the heights).

You are indeed missing something. TEITS was very clearly referring to mild westerlies being predicted to be blasted well into Europe by the 6th of Feb but that outcome is not forecast in current output. He correctly pointed out that further out low pressure systems are being predicted to blast much further east yet the European block tends to be holding strong. At no point did he deny it is currently wet or that low pressure is stalling over the UK. Re-read his post.

[Singularity]

 

The Euro low has a better shape to it but the block is not as well focused over Scandi. Could see the south maintain a cold feed from here on but the north could see westerlies for a little longer.

I'd stay to watch the rest of the run roll out but I'm too busy for such casual activities 

[Gowon]

That's a solid brick wall..!

Good trends again on the 12z

 

[frosty ground]

A Classic undercut from the east..... Front dieing in situ.

[IDO]

10 minutes ago, Seasonality said:

You are indeed missing something. TEITS was very clearly referring to mild westerlies being predicted to be blasted well into Europe by the 6th of Feb but that outcome is not forecast in current output. He correctly pointed out that further out low pressure systems are being predicted to blast much further east yet the European block tends to be holding strong. At no point did he deny it is currently wet or that low pressure is stalling over the UK. Re-read his post.

I was just pointing out the UK perspective, and of course your location the Europe picture is more interesting, as it really does not have much interest if Poland is snowed in and the UK is in a westerly flow; the same for the US going into the freezer when  the forecast was much milder! For my location the block being more persuasive has made little difference as to surface conditions, that being my point. I have no interest in that block bringing a continental flow for the last remnants of the winter as I want snow rather than cold.

The GEM moving from one cluster to another:

0z  12z

Which is my point re the models clueless at the moment. Expect changes run to run, cross and inter model.

Edited January 31, 2017 by IDO

[Ali1977]

Try your best Atlantic , but you ain't winning this battle. This isn't deep FI and with UKMO support this is quite an interesting period. If ECM follows suite surely it has a good chance of verifying in some shape or form (the block), getting a big freeze is trickier. We just need Ian F to have some more positive tweet.

Day 10 = very pleasant viewing :-)

Edited January 31, 2017 by Ali1977

[chris55]

Some really fascinating output from the ops at the moment, this Arctic/Scandi high is causing some inter run fluctuations. The differences between the 00-06-12z GFS are quite big even in the mid term.

At 120 we are getting some nice southerly lows, but losing the prospect of the early arrival of the cold pool

However by 213 the UK is freezing and that cold pool to the east is just monumental!!

UKMO ramps up the Atlantic low at 144, but still loaded with potential going forward with the high holding its latitude and a nice Italy low in place

 

 

This Scandi/Arctic high really has appeared out of nowhere!!! I cant remember any means or anomalies picking it up a few days back!! Just shows how things can quickly evolve when it comes to the NWP.

 

 

[Gowon]

What a sight.. Big block to our east and another in the Atlantic

 

[Harsh Climate]

 Only one way this run is going and that's to the freezer!

[northwestsnow]

Classic stuff from gfs, really hoping it has the correct handle on this now.

Ukmo, not sure its as good as gfs at 144, looks kind of similar..need that huge low to disrupt

 

 

 

Edited January 31, 2017 by northwestsnow

[chris55]

12 minutes ago, D.V.R said:

That's a solid brick wall..!

Good trends again on the 12z

 

I do like a black hole anomaly!! And that a nice place to have the centre!!! Solid high lat block there!

[frosty ground]

5 minutes ago, IDO said:

I was just pointing out the UK perspective, and of course your location the Europe picture is more interesting, as it really does not have much interest if Poland is snowed in and the UK is in a westerly flow; the same for the US going into the freezer when  the forecast was much milder! For my location the block being more persuasive has made little difference as to surface conditions, that being my point. I have no interest in that block bringing a continental flow for the last remnants of the winter as I want snow rather than cold.

The GEM moving from one cluster to another:

0z  12z

Which is my point re the models clueless at the moment. Expect changes run to run, cross and inter model.

That run is different for the whole of europe, never mind the UK.

[Seasonality]

That is an utter monster of a cold pool slowly enveloping Europe on this run. Compare with the 06z. A real beast from the east if ever there was one. Upgrade!

[Stu_London]

12z has us partying like it's 1991!

[Day 10]

C'MON cold that's it, keep marching west and bring the powder snow with you

[chris55]

10 minutes ago, IDO said:

I was just pointing out the UK perspective, and of course your location the Europe picture is more interesting, as it really does not have much interest if Poland is snowed in and the UK is in a westerly flow; the same for the US going into the freezer when  the forecast was much milder! For my location the block being more persuasive has made little difference as to surface conditions, that being my point. I have no interest in that block bringing a continental flow for the last remnants of the winter as I want snow rather than cold.

The GEM moving from one cluster to another:

0z  12z

Which is my point re the models clueless at the moment. Expect changes run to run, cross and inter model.

Thats a serious swing from the GEM op, just highlights the volatility of such a pattern.

[Gowon]

1 minute ago, chris55 said:

I do like a black hole anomaly!! And that a nice place to have the centre!!! Solid high lat block there!

Me too..  I'm trying not to get too exited though 

[winterof79]

4 minutes ago, northwestsnow said:

Classic stuff from gfs, really hoping it has the correct handle on this now.

Ukmo, not sure its as good as gfs at 144, looks kind of similar..

 

 

GFS

UKMO Colder in Europe

[frosty ground]

The GEM still finds the same pattern. 

[Mucka]

8 minutes ago, northwestsnow said:

Classic stuff from gfs, really hoping it has the correct handle on this now.

Ukmo, not sure its as good as gfs at 144, looks kind of similar..need that huge low to disrupt

 

 

 

The block looks well aligned and if anything a tad further West than GFS but the bowling ball low in the Atlantic could be better. Still, it would not be shifting that block in a hurry and would be sure to disrupt.

The good news is they are fairly similar with the well aligned impenetrable block forming. 

Edited January 31, 2017 by Mucka

[Ali1977]

1 minute ago, chris55 said:

Thats a serious swing from the GEM op, just highlights the volatility of such a pattern.

Yeah that's a shame, I know it's the GEM but still goes to show that FI isn't much further than this weekend - it'll be v dissapointing if the ECM follows the GEM - -and without the METO onboard for any type of Easterly it could well go that way.  

Tonights BBC long range may mention the possibility I guess.

[northwestsnow]

2 minutes ago, winterof79 said:

GFS

UKMO Colder in Europe

But perhaps critically the scandy high is further north on gfs...not much in it tho.